While working on finishing up the doxygen->numpydoc conversion, I noticed that CalibrateTask and CharacterizeImageTask (and likely others) have redundant names in their return structs. Eli Rykoff added docstrings to the `run()` `Returns` field noting that they are "for compatibility", but those are actually there for the gen3 runQuantum output connections, while the old names are "for compatibility".

I don't think we have a way to deprecate return struct names, but we can at least make the docstrings more informative as to which are used by the pipetask infrastructure, vs. which are the old names that could be phased out in the future. I don't know if there is anything else we can or should do about these.